arXiv subjects

Paul Knowles

Publications and source records attributed to Paul Knowles.

6 recordsLinked to original sources

arXiv2024

Data-Centric Design: Introducing An Informatics Domain Model And Core Data Ontology For Computational Systems

The Core Data Ontology (CDO) and the Informatics Domain Model represent a transformative approach to computational systems, shifting from traditional node-centric designs to a data-centric paradigm. This paper introduces a framework where data is categorized into four modalities: objects, events, concepts, and actions. This quadrimodal structure enhances data security, semantic interoperability, and scalability across distributed data ecosystems. The CDO offers a comprehensive ontology that supports AI development, role-based access control, and multimodal data management. By focusing on the intrinsic value of data, the Informatics Domain Model redefines system architectures to prioritize data security, provenance, and auditability, addressing vulnerabilities in current models. The paper outlines the methodology for developing the CDO, explores its practical applications in fields such as AI, robotics, and legal compliance, and discusses future directions for scalable, decentralized, and interoperable data ecosystems.

cs.DC↗

arXiv2023

Distributed Governance: a Principal-Agent Approach to Data Governance -- Part 1 Background & Core Definitions

To address the need for regulating digital technologies without hampering innovation or pre-digital transformation regulatory frameworks, we provide a model to evolve Data governance toward Information governance and precise the relation between these two terms. This model bridges digital and non-digital information exchange. By considering the question of governed data usage through the angle of the Principal-Agent problem, we build a distributed governance model based on Autonomous Principals defined as entities capable of choice, therefore capable of exercising a transactional sovereignty. Extending the legal concept of the privacy sphere to a functional equivalent in the digital space leads to the construction of a digital self to which rights and accountability can be attached. Ecosystems, defined as communities of autonomous principals bound by a legitimate authority, provide the basis of interacting structures of increasing complexity endowed with a self-replicating property that mirrors physical world governance systems. The model proposes a governance concept for multi-stakeholder information systems operating across jurisdictions. Using recent software engineering advances in decentralised authentication and semantics, we provide a framework, Dynamic Data Economy to deploy a distributed governance model embedding checks and balance between human and technological governance. Domain specific governance models are left for further publications. Similarly, the technical questions related to the connection between a digital-self and its physical world controller (e.g biometric binding) will be treated in upcoming publications.

cs.CY↗

arXiv2016

Laser Spectroscopy of Muonic Atoms and Ions

Laser spectroscopy of the Lamb shift (2S-2P energy difference) in light muonic atoms or ions, in which one negative muon $\mu^-$ is bound to a nucleus, has been performed. The measurements yield significantly improved values of the root-mean-square charge radii of the nuclei, owing to the large muon mass, which results in a vastly increased muon wave function overlap with the nucleus. The values of the proton and deuteron radii are 10 and 3 times more accurate than the respective CODATA values, but 7 standard deviations smaller. Data on muonic helium-3 and -4 ions is being analyzed and will give new insights. In future, the (magnetic) Zemach radii of the proton and the helium-3 nuclei will be determined from laser spectroscopy of the 1S hyperfine splittings, and the Lamb shifts of muonic Li, Be and B can be used to improve the respective charge radii.

physics.atom-ph↗

arXiv2014

Measurement of the scalar third-order electric polarizability of the Cs ground state using CPT-spectroscopy in Ramsey geometry

The AC Stark shift induced by blackbody radiation is a major source of systematic uncertainty in present-day cesium microwave frequency standards. The shift is parametrized in terms of a third-order electric polarizability $α_0^{(3)}$ that can be inferred from the static electric field displacement of the clock transition resonance. In this paper, we report on an all-optical CPT pump-probe experiment measuring the differential polarizability $Δα_0^{(3)} = α_0^{(3)}(F{=}4) - α_0^{(3)}(F{=}3)$ on a thermal Cs atomic beam, from which we infer $ α_0^{(3)}(F{=}4) = 2.023(6)_{stat}(9)_{syst}~Hz/(kV/cm)^2$, which corresponds to a scalar Stark shift parameter $ k_{s} = -2.312(7)_{stat}(10)_{syst}~Hz/(kV/cm)^2$. The result agrees within two standard deviations with a recent measurement in an atomic fountain, and rules out another recent result obtained in a Cs vapor cell.

physics.atom-ph↗

arXiv2013

Lifetime and population of the 2S state in muonic protium and deuterium

Radiative deexcitation (RD) of the metastable 2S state of muonic protium and deuterium atoms has been observed. In muonic protium, we improve the precision on lifetime and population (formation probability) values for the short-lived μp(2S) component, and give an upper limit for RD of long-lived μp(2S) atoms. In muonic deuterium at 1 hPa, 3.1 +-0.3 % of all stopped muons form μd(2S) atoms. The short-lived 2S component has a population of 1.35 +0.57 -0.33 % and a lifetime of τ_short(μd) = 138 +32 -34 ns. We see evidence for RD of long-lived μd(2S) with a lifetime of τ_long(μd) = 1.15 +0.75 -0.53 μs. This is interpreted as formation and decay of excited muonic molecules.

physics.atom-ph↗

arXiv2006

Experimental study of laser detected magnetic resonance based on atomic alignment

We present an experimental study of the spectra produced by optical/radio-frequency double resonance in which resonant linearly polarized laser light is used in the optical pumping and detection processes. We show that the experimental spectra obtained for cesium are in excellent agreement with a very general theoretical model developed in our group and we investigate the limitations of this model. Finally, the results are discussed in view of their use in the study of relaxation processes in aligned alkali vapors.

physics.atom-ph↗